Inclinable jib for hoisting and transporting loads, in particular for cranes

ABSTRACT

An inclinable jib having a first beam with one end that is fixed to a lower king-pin to form a jib foot while the other end of the jib foot is pivotally connected to the base of a second beam which constitutes a jib head. A fixedly positioned winch is connected by means of a cable to the free end of the jib head to control the variations of inclination of the jib head and jib foot. A constant length sling has one end fastened to a fixed point while the other end is fastened to the jib foot with stop means in one embodiment being provided on the jib foot to make it mechanically integral with the jib head when the same is raised to a given position whereby the single winch may operate both jib foot and jib head in the selected manner. Various alternative embodiments including multiple arrangements of pulleys are provided to achieve the desired results.

United States Patent [191 Gallay [22] I Filed: Sept. 12, 1972 [21] Appl. No.: 288,318

[30] Foreign Application Priority Data Sept. 15.1971 France ..7l.33992 [52] US. Cl. 212/8 A, 212/144 [51] Int. Cl. B66c 23/00, B66c 23/62 [58] Field of Search 212/8 R, 8 A, 9, 144, 46 R,

212/46 A, 58 R, 58 A, 59 R [56] References Cited UNITED STATES PATENTS 2,722,319 11/1955 Stokes 212/8 3,037,641 6/1962 Potter et al. 4 212/144 X 3,252,585 5/1966 Wieschel 212/144 X June 11, 1974 Primary Examiner-Richard E. Aegerter Assistant ExaminerHadd Lane Attorney, Agent, or FirmWeiner, Basile & Weintraub [57] ABSTRACT An inclinable jib having a first beam with one end that is fixed to a lower king-pin to form a jib foot while the other end of the jib foot is pivotally connected to the base of a second beam which constitutes a jib head. A fixedly positioned winch is connected by means of a cable to the free end of the jib head to control the variations of inclination of the jib head and jib foot. A constant length sling has one end fastened to a fixed point while the other end is fastened to the jib foot with stop means in one embodiment being provided on the jib foot to make it mechanically integral with the jib head when the same is raised to a given position whereby the single winch may operate both jib foot and jib head in the selected manner. Various alternative embodiments including multiple arrangements of pulleys are provided to achieve the desired results.

9 Claims, 10 Drawing Figures PATENTEDJHH m $815759 sum ear 4 1 INCLINABLE JIB FOR norsrmc AND TRANSPORTING LOADS, IN PARTICULAR FOR CRANES The present invention relates to a jib for a hoisting gear, such as a crane, or the like. Said jib is made up of two members, one of which is linked to the end of the other, to wit, a jib foot and a jib head, the end of said jib head being provided with load-hoisting means.

BACKGROUND OF THE INVENTION winch for controlling the inclination of the jib head.

SUMMARY OF THE INVENTION The object of the present invention is to obviate the above drawbacks by providing a linked inclinable jib, the control of which is obtained in a very simple way, while new working abilities are available.

An inclinable jib according to the invention includes a fixed lower king-pin to which a first beam is linked to constitute the jib foot, while the base of a second beam constituting the jib head is linked to the opposite end of said first beam, a fixedly positioned winch being connected through a cable to the free end of the jib head to control the variations of inclination thereof, and it is characterized in that a constant-length sling has one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point, while stop means are provided on the jib foot to make the latter integral with the jib head when said jib head is raised up to a given position, so that, by means of the single winch, only the jib head steerable on the jib foot is actuated, as long as said jib head is inclined below its abutting position, whereas, after the jib head has reached said abutting position, said single winch actuates the rigid assembly constituted by the jib head and the jib foot.

According to a first embodiment of the invention, the operating cable, either provided with pulley-blocks or not, connects the winch drum directly to the end of a steerable king-rod, which, together with a stay and the jib head, defines an undeformable rocking triangle, the steerable king-rod being linked in the linking area of the two members of the jib, the stop means being constituted by two bearing heels, one of which is provided at the top of the jib foot, the other being provided on the base of the jib head. In a preferred embodiment, the winch, the securing point for the sling, the steerableking-rod, and the bearing heels are located rearwardly of the pin through which the jib head is linked to the jib foot.

According to a modified embodiment of the invention, the control cable connecting the winch drum to the linked king-rod and the end of the jib head, is fitted with reduction pulley-blocks completely housed within the jib foot. In thiscase, the pulley-block assembly preferably includes a first set of pulleys secured to the upper part of the jib foot, and inside the latter, a second movably mounted set of pulleys moves inside the lower part of the jib foot, being. fastened to the cable end concerned, which cable is returned outwards, that is, towards the linked king-rod and the jibhead, by pulleys.

According to a further modified embodiment of the invention, the pulley-block assembly comprising spaced sets of pulley disposed inside the jib foot is adapted to cooperate with a first stop, which is fixed but adjustable, and housed inside said jib foot, between the two sets of pulleys, which are both movable while a second fixed stop is provided above the upper set of pulleys, which is used as an anchoring point for one end of the constant-length sling, the latter being returned by pulleys towards another fixed anchoring point on the base of the crane. The jib foot and the jib head move together as a unit until the upper set of pulleys abuts the second fixed stop, the jib head being further inclined with respect to the jib foot until the lower set of pulleys abut first stop. In this case, it is not necessary to provide stop heels between the top of the jib foot and the base of the jib head, as the jib foot passes from its stationary condition to its raised condition when the sets of pulleys are each bearing against a stop.

In this latter case, the whole gear is preferably dimensioned in a manner such that, when the single winch pulls on the cable, the lower pulley-block assembly moves first, while the upper pulley-block assembly remains against its stop, said upper pulley-block assembly starting to be lowered, and causing both the jib foot and the jib head to rise, only when the lower pulley-block assembly bears against its stop.

The appended drawing, given by way of non-limiting example, will enable the features of the invention to be better understood.

FIG. 1 is a general view of a broken-jib crane according to the invention;

FIGS. 2, 3 and 4 illustrate several successive steps of the operation of said crane;

FIGS. 5 and 6 show a modification, with an inner pulley-block assembly;

FIGS. 7 and 8 show another modification, with inner pulley-blocks and stops;

FIGS. 9 and 10 show another adjustment of the modification of FIGS. 7 and 8.

FIGS. 1 to 4 show a broken-jib crane mounted, for instance, on the platform lot" a vehicle. The base of a hollow beam 3 is linked to a fixed king-pin 2 on the platform 1, and constitutes the foot of the jib. A pin 4 is provided at the front top of the jib foot 3. The lower end of a further beam 5 is linked to said pin 4, said beam 5 constituting the jib head. The free end of the jib head 5 is fitted with a hoisting cable 6 for handling the loads 7.

A king-rod 8 is linked to the pin 4. On the other hand, a cable 9, which is anchored to the end 10 of the jib head 5 and to the end 11 of the linked king-rod 8, is connected to a control winch 12 fixedly mounted on the platform 1. A pulley-block assembly 13 may be interposed in the path of the cable 9, in order to obtain a reduction.

Lastly, a constant-length sling 14 is secured through one of its ends to the pin 4, and through its other end to a fixed point 15 on the platform 1.

Behind the pin 4, a stop heel 16 is provided at the top of the jib foot 3, while another stop heel 17 is provided on the base of the jib head 5.

The operation is as follows:

When the jib foot 3 is inclined in a forward direction to an extent such (FIG. 3) that the sling l4 is taut, it will be seen that, if the winch 12 is operated for unwinding the cable 9, the jib foot 3 remains stationary, being supported by the sling 14, while the jib head 5 alone is lowered (direction of the arrow 18) to come, for instance, to the position shown in FIG. 1 or FIG. 4.

This makes it possible for a load 7 to be handled comthrough the heels l6 and 17, and behave as a single rigid beam. The raising occurs through the slackening of sling 14.

It is known that a pulley-block assembly such as 13 is a comparatively fragile device. The present invention makes it possible to protect it. To this end, according to the modification shown in FIGS. and 6, the cable 9 is passed round pulleys 22 and 23 which return it towards the base of the jib foot 3, inside which it goes up to a first movable set of pulleys 24. Said lower set 24 forms part of the pulley-block assembly 13, which includes, besides, an upper set 25 of pulleys, the axis pin of which is fixedly mounted inside the jib foot 3, at the top of the latter. Beyond the pulleysof the set 25, the cable is connected to the drum of the winch 12.

It will be seen that the operation is similar to that of the preceding embodiment, except that the elongations of the pulley-block assembly 13 take place under shelter, inside the jib foot 3 (FIG. 6). The lower set 24 of pulleys moves along the jib foot (arrow 26).

FIGS. 7 to show another modification wherein the pulley-block assembly 13 is housed inside the jib foot 3. Here, the two sets of pulleys of the pulley-block assembly 13, that is, the lower set 24 and an upper set 27, are movable. The pin for the upper set of pulleys 27 is used as an anchoring point for the constant-length sling 14, the latter remaining, besides, connected to the fixed point on the platform 1. A pulley 28 returns the sling to the upper part of the jib foot 3, so that the tension of the sling 14 tends to lift the set of pulleys 27 (arrow 29). The extent of this lifting motion is limited by a fixed stop 30 integral with the jib foot 3.

On the other hand, a fixed stop 31, the location of which is adjustable, is provided between the two pulley sets 24 and 27, so as to act as a stop for the lower set 24 when the latter rises.

Lastly, the whole gear is dimensioned in a manner such that, when the two sets 24 and 27 of pulleys are bearing against their respective stops (FIG. 10), the power required for pulling the upper set 27 downwards is higher than that required for pulling the lower set 24 downwards, it being understood that the winch 12 is simultaneously operated for slackening the cable.

It will be noted, besides, that in this case the linking pin 4 for the jib foot 3 and the jib head 5 may be located at the front, or in the middle, or else at the rear of said two members, without it being necessary to provide the stop heels 16 and 17.

The operation is as follows:

Starting from the position shown in FIG. 7 (only the upper set 27 bearing against its stop), the winch 12- being operated for slackening the cable, it will be seen that only the lower set 24 of pulleys is lowered (arrow 32), so that the jib head 5 is lowered too (arrow 33), while the upper set 27 of pulleys and the jib foot 3 remain stationary.

On the contrary, if the winch 12 is operated for pulling the cable, this causes the lower set 24 to rise till it comes to bear against the stop 31, in which position the jib foot 3 and the jib head 5 form an angle 34 which will remain unchanged if the pulling on the cable proceeds by means of the winch 12. As a matter of fact, beyond said position, as the lower set 24 of pulleys is stationary, it is the upper set 27 which is lowered (arrow 35), which causes the simultaneous raising (arrow 36) of the now undeformable assembly constituted by the jib head 5 and the jib foot 3, which define between them the fixed angle 34.

It will be seen that said fixed angle 34 may be adjusted to any desired value, merely by moving the adjustable stop 31. FIGS. 9 and 10 show, by way of example, an adjustment making it possible to obtain the same result as in FIGS. 1 to 4, that is, when-the jib head 5 and the jib foot 3 are integral with each other (the lower set 24 of pulleys bearing against its stop 31), said jib foot 3 and said jib head 5 are prolonging each other (angle 34 being equal to I claim: I

1. An inclinable jib for hoisting and transporting loads, said jib comprising: a first beam; a fixed lower king-pin to which said first beam is linked to constitute a jib foot; a second beam constituting a jib head said second beam being linked to the opposite end of said first beam, a fixedly positioned winch being connected through a cable to the free end of the jib'head to control the variations of inclination thereof; a constantlength sling having one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point; stop means on the jib foot to make the latter integral with the jib head when said jib head is raised up to a given position, so that, by means of the single winch, only the jib head steerable on the jib foot is actuated, as long as said jib head is inclined below its abutting position, whereas, after the jib head has reached said abutting position, said single winch actuates the rigid assembly constituted by the jib head and the jib foot.

2. An inclinable jib according to claim 1, characterized in that the upper end of the sling is secured directly to the top of the jib foot.

3. An inclinable jib as defined in claim 1 wherein said cable connects the winch drum directly to the end of a second steerable king-rod, which, together with a stay and the jib head, defines an undeformable rocking triangle, said second steerable king-rod being linked in the linking area for the two members of the jib, the stop means being constituted by two bearing heels, one of which is provided at the top of the jib foot, while the other is provided at the base of the jib head.

4. An inclinable jib as defined in claim 3 wherein the winch, the securing point for the sling, the steerable king-rod, and the bearing heels are located rearwardly of the pin through which the jib head is linked to the jib foot.

5. An inclinable jib as defined in claim 3 wherein the control cable connecting the winch drum to the linked king-rod and to the end of the jib head is fitted with re duction pulley-blocks completely housed within the jib foot.

6. An inclinable jib for hoisting and transporting loads, said jib comprising: a first beam; a fixed lower king-pin to which said first beam is linked to constitute a jib foot; asecond beam constituting a jib head said second beam being linked to the opposite end of said first beam; afixedly positioned winch being connected through a cable to the free end of the jib head to control the variations of inclination thereof; a constantlength sling having one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point, stop means on the jib foot to make the latter integral with the jib head when said jib head is raised up to a given position, so that, by means of the single winch, only the jib head steerable on the jib foot is actuated, as long as said jib head is inclined below its abutting position, whereas, after the jib head has reached said abutting position, said single winch actuates the rigid assembly constituted by the jib head and the jib foot; a first set of pulleys secured to the upper part of said jib foot, and inside the latter, a second and movable set of pulleys movably mounted inside the lower part of said jib foot, said second set of pulleys being fastened to said cable end concerned, which cable is returned outwards towards the linked king-rod and the jib head, by third pulleys.

7. An inclinable jib for hoisting and transporting loads, said jib comprising: a first beam; a fixed lower king-pin to which said first beam is linked to constitute a jib foot; a second beam constituting a jib head said second beam being linked to the opposite end of said first beam, a fixedly positioned winch being connected through a cable to the free end of the jib head to control the variations of inclination thereof; a constantlength sling being one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point, a pulley-block assembly comprising spaced sets of pulleys disposed inside the jib foot and adapted to cooperate with a first stop, which is fixed but adjustable, and housed inside said jib foot between said sets of pulleys, which are both movable; a second fixed stop provided above the upper set of pulleys, which is used as an anchoring point for one end of said constantlength sling, the latter being returned by pulleys towards said fixed anchoring point; said jib foot and said jib head moving together as a unit until said upper set of pulleys abuts said second fixed stop, said jib foot being further inclined with respect to said jib foot until said lower set of pulleys abuts said first stop.

8. An inclinable jib according to claim 7, characterized in that the whole gear is dimensioned in a manner such that, when the single winch pulls on the cable, the lower pulley-block assembly moves first, while the upper pulley-block assembly keeps bearing against its stop, said upper pulley-block assembly starting to be lowered, and causing both the jib foot and the jib head to rise, only after the lower pulley-block assembly has come to bear against its stop.

9. An inclinable jib according to claim 1, characterized in that the constant length of the sling is adjustable, depending on the inclination desired for the jib foot. 

1. An inclinable jib for hoisting and transporting loads, said jib comprising: a first beam; a fixed lower king-pin to which said first beam is linked to constitute a jib foot; a second beam constituting a jib head said second beam being linked to the opposite end of said first beam, a fixedly positioned winch being connected through a cable to the free end of the jib head to control the variations of inclination thereof; a constant-length sling having one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point; stop means on the jib foot to make the latter integral with the jib head when said jib head is raised up to a given position, so that, by means of the single winch, only the jib head steerable on the jib foot is actuated, as long as said jib head is inclined below its abutting position, whereas, after the jib head has reached said abutting position, said single winch actuates the rigid assembly constituted by the jib head and the jib foot.
 2. An inclinable jib according to claim 1, characterized in that the upper end of the sling is secured directly to the top of the jib foot.
 3. An inclinable jib as defined in claim 1 wherein said cable connects the winch drum directly to the end of a second steerable king-rod, which, together with a stay and the jib head, defines an undeformable rocking triangle, said second steerable king-rod being linked in the linking area for the two members of the jib, the stop means being constituted by two bearing heels, one of which is provided at the top of the jib foot, while the other is provided at the base of the jib head.
 4. An inclinable jib as defined in claim 3 wherein the winch, the securing point for the sling, the steerable king-rod, and the bearing heels are located rearwardly of the pin through which the jib head is linked to the jib foot.
 5. An inclinable jib as defined in claim 3 wherein the control cable connecting the winch drum to the linked king-rod and to the end of the jib head is fitted with reduction pulley-blocks completely housed within the jib foot.
 6. An inclinable jib for hoisting and transporting loads, said jib comprising: a first beam; a fixed lower king-pin to which said first beam is linked to constitute a jib foot; a second beam constituting a jib head said second beam being linked to the opposite end of said first beam; a fixedly positioned winch being connected through a cable to the free end of the jib head to control the variations of inclination thereof; a constant-length sling having one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point, stop means on the jib foot to make the latter integral with the jib head when said jib head is raised up to a given position, so that, by means of the single winch, only the jib head steerable on the jib foot is actuated, as long as said jib head is inclined below its abutting position, whereas, after the jib head has reached said abutting position, said single winch actuates the rigid assembly constituted by the jib head and the jib foot; a first set of pulleys secured to the upper part of said jib foot, and inside the latter, a second and movable set of pulleys movably mounted inside the lower part of said jib foot, said second set of pulleys being fastened to said cable end concerned, which cable is returned outwards towards the linked king-rod and the jib head, by third pulleys.
 7. An inclinable jib for hoisting and transporting loads, said jib comprising: a first beam; a fixed lower king-pin to which said first beam is linked to constitute a jib foot; a second beam constituting a jib head said second beam being linked to the opposite end of said first beam, a fixedly positioned winch being conneCted through a cable to the free end of the jib head to control the variations of inclination thereof; a constant-length sling being one of its ends connected to the top of the jib foot, and its other end fastened to a fixed point, a pulley-block assembly comprising spaced sets of pulleys disposed inside the jib foot and adapted to cooperate with a first stop, which is fixed but adjustable, and housed inside said jib foot between said sets of pulleys, which are both movable; a second fixed stop provided above the upper set of pulleys, which is used as an anchoring point for one end of said constant-length sling, the latter being returned by pulleys towards said fixed anchoring point; said jib foot and said jib head moving together as a unit until said upper set of pulleys abuts said second fixed stop, said jib foot being further inclined with respect to said jib foot until said lower set of pulleys abuts said first stop.
 8. An inclinable jib according to claim 7, characterized in that the whole gear is dimensioned in a manner such that, when the single winch pulls on the cable, the lower pulley-block assembly moves first, while the upper pulley-block assembly keeps bearing against its stop, said upper pulley-block assembly starting to be lowered, and causing both the jib foot and the jib head to rise, only after the lower pulley-block assembly has come to bear against its stop.
 9. An inclinable jib according to claim 1, characterized in that the constant length of the sling is adjustable, depending on the inclination desired for the jib foot. 